We are very impressed with the effectiveness of a new combination of two drugs, docetaxel (Taxotere), and doxorubicin (Adriamycin) when they are used in breast cancer patients. This combination, which we call DD, has been tested in women with advanced cancer, and it appears to be very effective in causing shrinkage of tumors. DD has been tested in women whose cancer has spread beyond the breast and underarm lymph nodes. Given its effectiveness in more advanced cancer, we hope to show that it will shrink localized breast tumors over 90% of the time, and will lead to simpler surgical procedures, a higher rate of breast preservation, and a better outcome overall. In addition to testing the effectiveness of DD chemotherapy, this trial will evaluate the usefulness of using a simple test, known as the erythromycin breath test (ERMBT), in predicting how patients will tolerate the chemotherapy. In the future, this test may allow us to tailor the dose of chemotherapy to an individual patient's metabolism. In summary, this research trial examines the use of DD chemotherapy prior to surgery in women with localized breast cancer. With this clinical trial, we will determine the number of women who have an excellent response to DD, the number of women who can have breast preservation rather than mastectomy (if that is what she desires), and we will examine the effect that the DD chemotherapy has on the tumor itself. We hope that by learning about more effective chemotherapy combinations in this way, we will be able to improve the chances for cure of breast cancer. This trial will include healthy women with primary breast tumors greater than 1 cm that have been diagnosed by core needle biopsy, but whose tumors have not been completely removed yet. Candidates for this trial may not have received any other breast cancer treatments, including surgery, radiation, chemotherapy, or tamoxifen. The candidate may not be pregnant or breast feeding, and must agree to practice effective birth control during the study if she is of childbearing age.